2) Calculate the percent composition of each element in Mgso,

3) Calculate the percentage of each element in Ag,o.

Answer:

pH = 12.90

Explanation:

THe reaction of HNO₃ with KOH is:

HNO₂ + KOH → KNO₂ + H₂O

That means 1 mole of nitrous acid reacts per mole of potassium hydroxide.

To solve this question, we need to find the moles of each reactant:

Moles HNO₂:

0.0179L * (0.458mol / L) = 0.00820 moles

Moles KOH:

0.0334L * (0.368mol / L) = 0.01229 moles

That means KOH is in excess. The moles in excess are:

0.01229 moles - 0.00820 moles = 0.00409 moles KOH = Moles OH⁻

The [OH⁻] is -Total volume = 17.9mL+33.4mL = 51.3mL = 0.0513L-:

0.00409 moles / 0.0513L =

0.0797M =[OH⁻]

pOH = -log[OH⁻] = 1.098

pH = 14 - pOH

Answer:

A. When two aqueous solutions are mixed, a precipitate is formed.

Explanation:

The precipitate (a solid substance that falls from the liquid) is the result of a chemical reaction taking place between the liquids.

The other three answer choices are indicative of physical changes (temperature change, phase change, color change).

When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

Chemical change are those changes in which substance changes chemical composition. These changes are permanent changes. In chemical change new substances formed and in chemical change substances can not get back into its original form. It is irreversible change.

Physical changes are those changes in which substance changes physical properties only. Properties like temperature, pressure, shape, color, size, state (solid, liquid and gas). These changes are temporary in nature. In physical change no new substances formed. It is reversible change.

Now, check all the options one by one:

Option (A): When two aqueous solutions are mixed, a precipitate is formed is a chemical change. Since precipitation indicate a chemical reaction (that is double displacement reaction).

Option (B): As ammonium nitrate dissolved in water causes the temperature to decrease is a physical change because heat energy is absorbed here and it is a endothermic reaction.

Option (C): Alcohol evaporates when left in an open container is a physical change because evaporation is a physical change as it changes the state from liquid state to gas state.

Option (D): Water is added to blue copper (II) chloride solution. The resulting mixture if lighter blue in color is a physical change as properties like change in color is physical change.  

Thus, from above conclusion we can say that When two aqueous solutions are mixed, a precipitate is formed indicates that a chemical change has occurred.  

Hence, option A is correct answer.

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[tex] \huge \colorbox{pink}{Answer☟︎︎︎}[/tex]

When ice melts, liquid water performs the act of erosion by carrying away the tiny rock fragments lost in the split. This specific process (the freeze-thaw cycle) is called frost weathering or cryofracturing. Temperature changes can also contribute to mechanical weathering in a process called thermal stress.

Answer:

Nacl compound contain ionic bonds because sodium is metal and chlorin is nonmetal

Answer:

Explanation:

C

2.00 M is the molarity of a solution made by dissolving 1.25 mol of HCl in enough water to make 625 mL of solution.

A mole is defined as 6.02214076 ×  of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

[tex]Molality = \frac{Moles \;solute}{Volume \;of \;solution \;in \;litre}[/tex]

[tex]Molality = \frac{1.25}{0.625}[/tex]

Molality = 2.00 M

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Answer:

your finger becomes negatively charged

Explanation:

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Answer:

Due to the circulation of the wind and water the trash will continue to go around in a circle thus causing it to be trapped there.

Answer:

Overall enthalpy change for the formation of one mole nitric acid from nitrogen, hydrogen and oxygen, ΔH = -376 KJ

Note: the question is incomplete. The complete question is given below:

Nitric acid can be formed in two steps from the atmospheric gases nitrogen and oxygen, plus hydrogen prepared by reforming natural gas. In the first step, nitrogen and hydrogen react to form ammonia: N₂(g) + 3H₂(g)  → 2NH₃(g) ΔH = -92. kJ In the second step, ammonia and oxygen react to form nitric acid and water: NH3(g) + 2O2(g) → HNO3(g) + H2O(g) ΔH = -330. kJ Calculate the net change in enthalpy for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen from these reactions. Round your answer to the nearest kJ.

Explanation:

From Hess's law of constant heat summation, the total enthalpy change for a reaction is the sum of all changes without regard to the number of multiple stages or steps involved in a reaction.

Enthalpy is a state function as it does not depend on the path taken to attain its value. Therefore, the summation of the enthalpy changes involved in the individual steps in the reaction of the formation of nitric acid will be equal to the enthalpy change of the overall reaction step.

For the first reaction step:

N₂(g) + 3H₂(g)  →  2NH₃(g) ΔH = -92. kJ

For the second reaction step:

NH₃(g) + 2O₂(g) → HNO3(g) + H2O(g) ΔH = -330. kJ

Overall reaction step:

[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]H₂(g) + 2O₂(g)  →  HNO₃ + H₂O  ΔH = ?

The overall reaction for the formation of one mole of nitric acid from nitrogen, hydrogen and oxygen shows that the first reaction step should be divided by 2

[tex]\frac{1}{2}[/tex]N₂(g) + [tex]\frac{3}{2}[/tex]3H₂(g)  →  NH₃(g) ΔH = -46. kJ

Overall enthalpy change, ΔH = ΔH₁ + ΔH₂

Overall enthalpy change,ΔH = (-46 KJ) + (-330 KJ)

Overall enthalpy change,ΔH = -376 KJ

Explanation:

if they aren't in a solvent, then you magnetize first, to remove the iron fillings, secondly, you can sieve to separate the sand and pebbles

Separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips.

To separate their soil mixes using the tools you have supplied, ask the groups to develop a plan. They might consider using forceps to separate the soil, shaking it between two tumblers, placing it in a water-filled tumbler, or pouring it through air. Invite student groups to present their ideas.

Pbbles  - Separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips. As a strainer, a colander or a section of window screen works well. Iron fillings Using a magnet, it is simple to remove the tiny iron filings from the mixture.

Therefore, separate the pebbles by either straining them out or pulling each one out separately with tweezers or your fingertips.

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Answer:

Explanation:

decomposers

Answer:

Magnetic field

Explanation:

Answer:

case1.

The addition of acid and base leads to a change in pH of the water when adding to deionized water due to fact that acid and bases dissociated in dissolving in water. If the H+ ion increases in the water as acid addition hikes it, it will result in decreasing the pH value. The intensity of the acid also affects the dissociation of the ions.

case2

Buffers are normally formed by weak acid and its conjugate base, and adding acid to the buffer it absorbs the H+ ions so the pH will be lower and adding base or increase of OH- conjugate base resists the pH value to increase.

Answer:

Ball 16 oz Pint Mason Jar outer dimensions are 5.2 height by 3.2 diameter – which could hold approximately 390 jelly beans. Ball 32 oz Quart Mason Jar outer dimensions are 6.9 height by 3.9 diameter – which could hold approximately 804 jelly beans.Oct 5, 2017

Explanation:

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Answer:

100 jellybeans

Explanation:

Mass of Jar with jellybeans=230 grams

Mass of Jar=30 grams

Mass of 1 jellybean=2 grams

Mass of Jellybeans in jar

=Mass of Jar with jellybeans-Mass of Jar

=230 grams - 30 grams

=200 grams

2 grams=1 jellybean

1 gram=1/2 jellybean

200 grams=200*(1/2) jellybeans=100 jellybeans

Answer: There are 4.375 moles in 2.5 L of 1.75 M [tex]Na_2CO_3[/tex]

Explanation:

To calculate the number of moles for given molarity, we use the equation:

[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution (in L)}}[/tex]      

Molarity of solution = 1.75 M

Volume of solution = 2.5 L  

Putting values in equation , we get:

[tex]1.75M=\frac{\text{Moles of} Na_2CO_3}{2.5L}\\\\\text{Moles of }Na_2CO_3=1.75mol/L\times 2.5L=4.375mol[/tex]

The question is incomplete, the complete question is;

Draw Lewis structures for the following compounds/ions.

Decide if the compound/ion listed can satisfy the octet rule (duet rule for H), if so choose Satisfies Octet Rule from the drop down menu.

If the compound/ion cannot satisfy the octet rule for one of the atoms in the formula, choose one of the following three reasons why;

Too many valence electrons (more than eight), Too few valence electrons (fewer than eight), or Odd # of valence electrons.

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  KrCl2

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  PCl3

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  BeH2

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  NO3-

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  SeO22-

Satisfies Octet Rule Too many valence electrons Too few valence electrons Odd # of valence electrons  SO2

Answer:

See explanation

Explanation:

Let us consider the number of valence electrons in each of the species. This will let us know whether the specie satisfies the octet rule or not.

KrCl2 has a total of 22 valence electrons. This implies that there are too many valence electrons hence the compound does not satisfy the octet rule.

For PCl3, there are 26 valence electrons. This compound satisfies the octet rule.

For BeH2, there are four valence electrons. This number of valence electrons is too few hence BeH2 does not satisfy the octet rule.

NO3^- has 24 valence electrons and is represented using resonance structures. Its resonance structures show that the specie satisfies the octet rule.

SeO2^2- has 20 valence electrons. This specie satisfies the octet rule.

SO2 has 18 valence electrons and is represented by resonance structures which satisfy the octet rule.

Its the warm air what helps them also of energy of the sun

Answer:

[tex]m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3[/tex]

Explanation:

Hello!

In this case, since the decomposition of sodium hydrogen carbonate is:

[tex]2NaHCO_3(s)\rightarrow Na_2CO_3(s)+H_2O(g)+CO_2(g)[/tex]

Thus, since there is a 2:1 mole ratio between the sodium hydrogen carbonate and sodium carbonate, and the molar masses are 84.01 and 105.99 g/mol respectively, we obtain the following theoretical yield:

[tex]m_{Na_2CO_3}^{theoretical}=10.52gNaHCO_3*\frac{1molNaHCO_3}{84.01gNaHCO_3}*\frac{1molNa_2CO_3}{2molNaHCO_3} *\frac{105.99gNa_2CO_3}{1molNa_2CO_3}\\\\ m_{Na_2CO_3}^{theoretical}=6.636gNa_2CO_3[/tex]

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Answer:

It is possible not all of the water was evaporated from the sand, causing the recovered mass to be higher.

Explanation:

If not all the water is evaporated from the sand so the recovered mass to be higher than the sand from which more water is evaporated because evaporation of little amount of water causes less decrease in the recovered mass as compared to that sand from which more water is evaporated so more decrease occur in the recovered mass.

Answer:

Mass

Explanation:

based on the law of conservation of energy its it atoms hold by strong chemical bonds

Answer: A person engaged in the practice of anthropology. Anthropology is the study of aspects of humans within past and present societies. Social anthropology, cultural anthropology and philosophical anthropology study the norms and values of societies.

Explanation: I HOPE THIS HELPS U AND ANSWERS UR QUESTION!!! Stay safe and healthy!

Answer:

If a pure compound is distilled, the temperature of the head will be compared to the temperature of the pot. However, if there is an impurity present that strongly interacts with the molecules of the liquid, then the temperature must be increased to increase the vapor pressure of the liquid, eventually to atmospheric pressure, allowing the liquid to boil. Therefore, at the boiling point, the temperature of the pot will be higher than the temperature of the head.

Explanation:

when temperatures increase, pressures also do so, thus reaching boiling points where liquid states become gaseous.

Answer:

N

Explanation:

Electronegativity increases as you move from left to right across a period, and decreases as you move down the groups.

Answer:

N .. ........................

Answer:

the second answer choice i think

Explanation:

Answer:

2) A catalyst is not consumed in the course of a reaction.

Explanation:

A catalyst is a substance which increases the rate of  chemical reaction and remains chemically unchanged at the end of the reaction.  The addition of a catalyst increases the rate of both reversible and irreversible reactions. including reversible reactions involving a final equilibrium state. In reversible reactions, catalysts speed up the time for equilibrium to be attained.

Considering the given statements about catalysts:

1) In an equilibrium process, a catalyst increases the rate of the forward reaction, but leaves the rate of the reverse reaction unchanged.

False: A catalyst increases both the forward and reverse reaction rates equally, thereby allowing the system to reach equilibrium faster.

2) A catalyst is not consumed in the course of a reaction.

True: Catalysts are substances that increase reaction rates without being consumed in the reaction.

3) A catalyst must be carefully chosen to shift the equilibrium toward products.

False: A catalyst does not affect the extent or position equilibrium of a reaction since a catalyst speeds up both the forward and back reactions by  equal amounts , rather it helps a reaction achieve equilibrium faster.

Since there is excess hydrogen, that means that the concentration of hydrogen is not limiting.

According to the balanced chemical equation:

every mole of N2 and every 3 moles of H2 we obtain 2 moles of NH3. Since we have the amount of N2 and excess of hydrogen, we only need to work with the amount of N2.

1 mol of N2 will produce 2 moles of NH3

so now we can get a conversation tool :

moles of N2 * (2 moles of NH3/ 1 mole of N2) = moles of NH3

(2.22 mol of N2 x 2) ÷ 1 = 4.44 mol of NH3

Answer:

2kcl+ fe= Fecl2+2K

so coefficient required be 2 for kcl and 2 forK